Automatic traffic regulating system for street intersections



July 26, 1965 3. R088] ETAL 3,196,386

AUTOMATIC TRAFFIC REGULATING SYSTEM FOR STREET INTERSECTIONS Filed Feb.20. 1961 FIG. 2.

3 j jm k 3 ME Light Control CUT OFF 4 Q DELAY INVENTORS Bruno RossiCami/Io Calderoni mm a 4;

ATTORNEY United States Patent 3,196,386 AUTOMATIC TRAFFHC REGULATENGSYSTEM FOR STREET INTERSEQTEGNS Bruno Rossi and Camilla Calderoni, bothof Via Indipendenza 58, Bologna, Italy Filed Feb. 20, 1961, Ser. No.0,501 1 Claim. ((31. 349-31) The present invention has as its object anautomatic traffic regulating system of the type whose signals aresubject to control by the traffic at road intersections, at blind curveswhereby vehicles crossing the intersection are warned to stop or slowdown and thereby prevent accidents and at stop signs.

The automatic traffic regulating system of the invention comprises, incombination, vehicle-activated signaling means along each of the streetsof the intersection for closing one ormore electrical circuits bypassage of the vehicle over said means along the street route, anelectronic switching mechanism capable upon interruption by vehiculartraffic of the vehicle actuated signaling means to energize the circuitsand operate one or more visible signals and the visible signaling meanswhich indicate to the driver whether the route is free from vehiculartraffic, along a direction which the driver cannot perceive, therebyproviding the necessary trafiic inl formation to the driver to enablehim to proceed with complete safety.

The automatic traffic regulating and signaling system of the inventionprovides sufiicient and timely warning to vehicular trafiic ofintersection, main highway, dangerous, curve and road under constructionahead and avoids serious collision with faster moving main highwaytraffic for vehicles turning into or crossing main highways from a sidestreet, and for vehicles coming into hidden curves and unseen roadconstruction.

It is an important characteristic of the traffic signaling system of theinvention that the visible signaling system is actuated by but a singlevehicle.

Another advantage of the automatic signaling system of the invention isthe assurance that a vehicle coming in any direction into thedangerousarea on the highway will positively actuate the visible signaling systemto provide warning to oncoming trafiic from a different direction.

The foregoing objects and advantages of the invention will be betterunderstood by referring to the accompanying drawings which are for thepurpose of illustrating preferred embodiments of the invention and arenot intended to limit the scope or spirit of the invention, since manychanges in form and detail lying within the scope of the inventiondefined in the claim will be apparent to those skilled in the art.

In the drawings,

FIG. 1 shows a perspective view in diagrammatic form of the visiblesignaling means employed in the invention; and

FIG. 2 shows a plan view in diagrammatic form, the placement of thesignaling means of FIG. 1 at a through intersection.

The circuitry in the boxes shown in FIG. 2 including relays and timingelements which are ordinarily used are as disclosed in the United StatesPatent to Horni, No. 2,049,651. However, these details of Horni do notform any part of the present invention, being known to the art and theinvention differs in the manner in which the lighting device of FIG. 1herein is operated.

Upon approaching the intersection and mechanically actuating the speedcontact the signal lighting device of the invention is adapted to locateon the hanging box 5 the position of the car which has approached thelight along the cross route. A specific illustration will be seen,

3,195,385 Patented July 20, 1965 ice from bottom to top on the mainhighway shown in the vertical direction. The contact 4' actuates signallight 4 green) and this in turn provides an actuation of signal lights4" and 4" in box 5. These locations of actuation on the box providecomplete information to a vehicle which approaches on the secondaryhighway traveling in the counter direction, diagrammatically downwardlyor upwardly on the secondary road or a vehicle traveling in the oppositedirection on the main road.

Accordingly, it is seen that for each of the street contacts 1, 2, 3 and4 which are actuated by vehicles approaching the intersection from thefour directions to the intersection, there is a signal flashing tolocate the position of each vehicle and to inform the driver of eachvehicle concerning the position of every other vehicle approaching theintersection. In effect, the novel signaling device provides anextension for the view ofthe driver of each vehicle approaching theintersection to cover areas of approach ordinarily locked from his view.

It can readily be understood that the lighting color' system used forthis traffic identification function of the novel signaling device canbe varied to suit local and national highway standards and regulations.For example, the approach of vehicles on secondary roads will actuatethe warning signal and the color of red, amber, orange or yellow mightbe used on the main highway as well as on the secondary'highway topermit an effective warning within the experience under local highwayregulations. 1

The circuit which 'is actuated by the closing of the street contact toprovide the illuminated signal warning differs from the circuit which isemployed in patent to Horni, U.S. No. 2,049,651. 1

As shown in FIG. 2,- the automatic trafiic regulating system of thepresent inventionwill operate on any one of the treadles 1, 2, 3 and 4in the locations which are shown at the street intersection. It is onlyfor treadle 4 that the diagrammatic circuit comprising the time delaymeans and the light switch control is shown in the drawing. The timedelay and light switch control is also present for each of treadles 1,2and 3 and the operation is essentially the same. A car approaching thetraflic signal atthe intersection depresses treadle 4. Light 4', whichis the center light in the set facing the treadle approached andactuated by the car, is a green light and as a result of the actuationof the light control switch diagrammatically shown, lights 4' and 4' areilluminated as red lights.

In the combination of electric lamps in the trafiic signal boxrepresented by the series of lights 4, 4 and 4", the illustrative caseof FIG. 2 assumes that trafiic in the transverse direction on thehighway between treadles 1 and 3 represents the stream of trafiic on thecross street, while the trafiic at right angles thereto between treadles4 and 2. represents trafiic on the main highway. The car underconsideration is approaching the intersection after passing over treadle4.

As a result of the actuation of treadle 4, the cars on the cross streetare warned by the illumination of the red lights 4" and 4 that a car isapproaching from the direction of treadle 4.

In the embodiment of FIG. 2, the location of illuminated red light 4"warns a car approaching the signal box on the cross street from thedirection of treadle 1 that a car in cross trafiic approaches from theright. The location of illuminated red light 4" at the left of the box,when viewed by a driver approaching the main highway from the directionof treadle 3, conveys to this driver 3 the information that the carwhich approaches and illuminated the box is now approaching from theleft.

The distance of setback of street contacts 1, 2, 3 or 4 from theintersection varies in accordance with the average rate of speed orspeed limit control for main and secondary highways.

The street contacts 1, 2, 3 and 4 are a preferred example of vehicleactuated signaling means. It is preferred that the invention use atreadle of the mechanical type because of its simplicity, easyconstruction, easy maintenance and economy.

From the foregoing explanation, it will be seen that the, signaling isautomatic and can be controlled for time delay upon actuation of thevehicle actuated means on the street remote from the highwayintersection.

From the foregoing detailed description of the preferred embodiments ofvisible signaling box device 5 in 7 FIGS. 1 and 2 for trafiic control atintersections, it is seen that the novel arrangement of the inventiondiffers from those conventionally used in that each traveling vehicle,regardless of direction, actuates the traffic actuated signaling meansfor all traffic locations with the requirement that such actuation will,by closing a conventional type of light switch and time delay circuit,cause the lighting of .twosignals along the cross line of trafiicwhich'is' transverse to the line in which the vehicle is being drivenand a third signal in the main direction to indicate that the signal isoperating these signals being arranged geometrically to locate the trueposition -on the cross-highway of the car which actuates the vehiclesignaling means and thereby providing warnings in both directions on themain line of traffic and, at the same time, giving a warning in the onetransverse direction to the right or left of the signaling vehicle'at'the intersection.

The circuitry means used to post by traffic light signal- ,ing bothposition and direction at anintersection ,or at a curve for all carscoming in every direction differs from conventional circuitry by beingdirectly connected to a position light on the traffic signaling means.At the center of the box device 5 used in the array of lights shown inFIGS. 1 and 2, the box device comprises a light for driversposition',two lights for approaching vehicles position from both directions ofcross traffic at the intersection. The car coming in cross traflic fromthe right makes a visible signal in the array of three lights at theright side and a car coming from the left makes a visible signal at theleft side of the array of three lights. Each of the four sides arearranged with these three lights operating in identical sense. Therebyeach vehicle upon approaching the intersection posts its central lightand is warned by specific location of lights, right or left, actuated byvehicles in the same relative positions, right or left, when crossingthe intersection.

It is a critical feature of the invention that the automatic operationof the trafiic signaling meansemploys means for cutting off the trafiicsignal means after the vehicles have gone beyond the traflic signal. Forthis purpose, there may be used time delay devices of the conventionaltypes, and a specific illustration of a cutolf device may employ a motorin the circuit diagram shown in FIG. 2 of U.S. Patent to Neill, No.2,015,435, this motor operating by reverse rotation and being actuatedby a second detector. Or if desired, a more complex electronic timingcircuit of the type described in Barker, U.S. Patent No. 2,883,644 maybe employed. Any cutoff mechanism can be used and the details of thecutoff mechanism whether of the motor type as in Neill or the electronictype in Barker are not part of the present invention, these detailsbeing known in the art. It is 4 obviously preferred to use simplermechanisms of the known motor or clock type.

It will therefore be seen that the new operation of the system of theinvention comprises a specific type of self-posting actuation by thefirst vehicle approaching to register the operation of the trafiicsignaling means by lighting a light of smaller aperture therein, thisfirst lighting indicating posting of the approaching vehiclesimultaneously registering oneor more lights of larger aperture in thesignaling device facing the cross direction whereby approaching crosstraffic is immediately warned by the first vehicle, the warning mademore effective by the largeraperture and the location beingsimultaneously registered to the second or later approaching vehicle orvehicles by locating the larger lighting aperture for cross trafiic onthe same side as that from which the first vehicle approaches theintersection or curve. On all sides, at curve or intersection, allvehicles are warned of approach and location of all crossing vehicleswhich eluding a single element treadle occupying only one-half the widthof the road located along each of the streets of the intersection forlighting a trafiic signal; a traffic signal in'the form of a boxfurnished with three lights on each side of the box, each side facing astreet of the intersection; said box being placed overhead at theintersection to be visible approaching the intersection from alldirections; said three lights on each side of the box consisting of acenter light and two outer lights, said center light indicating freepassage and being smaller in diameter than said outer lights, while saidouter lights warn the approach of cross trafiic; light switching meansconnecting to and lying between each of said treadles and saidbox'signal which are energized by the move nient of thevehicle over thetreadle as the vehicle approaches the intersection, and time delay meansconnected to'said light switching means, said delay means maintainingthe trafiic signal in lit condition for a predetermined time afteractuation, the larger lights which are lit on the side of the boxrepresenting the side of the street from which the vehicle approachesand the larger "outer light being simultaneously lit on the oppositeside of the box as a warning light to provide warning on each of thesides of the box facing the cross trafiic, and to a later vehicle incross traffic that an earlier vehicle was passing through theintersection.

References Cited by the Examiner UNITED STATES PATENTS 7 NEIL C. READ,Primary Examiner.

THOMAS B. HABECKER, RUDOLPH V. ROLINEC,

Examiners.

